Implemented the first few functions.
Fold.
Compose functions.

See `pointfree -v '\a -> (:.) (k a)'`.
A v1 of filter.
Filter by folding.
Implement list concatenation.
Concatenate with foldRight.
Concatenate with flip foldRight.

This is some serious shit.
Flatten.
Implement flatMap.
Save type constructor examples that Tony wrote.
A dirty pattern matching implementation of seqOptional.